Methods

Quick reference

• 00:04 We're starting to get into more advanced topics, and
• 00:07 in this video I want to talk about methods.
• 00:09 And methods are very important for Ruby and any programming language.
• 00:13 And basically, a method is a block of code that
• 00:16 doesn't get executed when your program runs until you tell it to.
• 00:21 So it's a good way to keep chunks of code separate,
• 00:23 and only call them when you need them.
• 00:26 That's a good way to keep your code clean and clear, and
• 00:28 it's just a good programming thing that you're going to do.
• 00:30 So to create a method in Ruby, it's really simple.
• 00:33 You just define, you type def to define it, and then you name it.
• 00:38 So let's call this name.
• 00:40 And then you put these parentheses guys here, and
• 00:43 that's how we pass arguments into our method.
• 00:45 I'll show you about that in just a minute.
• 00:47 So below that we just type end, and now we've created a method.
• 00:50 It doesn't do anything, but it exists.
• 00:53 So inside of here we can write whatever code we want, right?
• 00:56 So we've seen this sort of general format before with our if statements, our loops.
• 01:00 You do something, you end something, in the middle is where the stuff goes.
• 01:03 So here I can just puts "Hello Bob".
• 01:07 So we save this.
• 01:08 Now, if I run this, nothing happened.
• 01:12 Because like I said, methods don't get run automatically when your program runs.
• 01:16 They only work, they only get called, if you call them, if you invoke them.
• 01:20 In order to invoke a method, you type its name.
• 01:24 In this case, it's name.
• 01:25 Now, we don't have to type puts, we don't have to do anything,
• 01:27 we just invoke the name of the method.
• 01:29 So now if we run it it says, Hello Bob.
• 01:31 So this is pretty interesting.
• 01:33 We can pass things into our method, right?
• 01:36 Let's change this guy to namer, we'll call him namer.
• 01:39 So let's say we want to pass a first_name.
• 01:44 And you don't have to put these spaces,
• 01:46 I just do it because I like the way it looks.
• 01:48 And let's say we want to output Hello.
• 01:52 And let's use our interpolation, with our little brackets, and go #{first_name}
• 01:57 So now, if I run this I'm going to get an error.
• 02:00 Watch, I got an error, because when I called it I didn't pass any arguments in,
• 02:05 and our program is looking for an argument, this first_name,
• 02:09 to be passed in.
• 02:10 So to pass in arguments to a method, you just type in those parentheses and
• 02:14 put whatever you want in there.
• 02:15 So let's say, John.
• 02:17 So now we're passing John into our method, and first_name becomes John.
• 02:23 It's almost like we went first_name = John, right?
• 02:28 But we don't have to explicitly do that, this thing right here does it for us.
• 02:33 So if we save this, now if we run it, it says Hello John.
• 02:37 If we change this to Tim, it doesn't matter what we change it to,
• 02:43 it gets passed into our method.
• 02:46 And then the code is executed, and it does whatever we've told it to do.
• 02:49 So in a very, very simplistic way, those are methods.
• 02:53 They're very important, they're very powerful.
• 02:55 We're going to use them forever with your programming,
• 02:57 it's just one of those things.
• 02:58 And in the next video, I'm going to talk a little bit more about methods.
• 03:01 We could talk for days about methods, but in the next video,
• 03:04 we're going to finish up methods and talk a little bit more in detail about them.

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